Answer:
The correct answer is A. Nadábamos
Explanation:
We used to swim, corresponds to the imperfect preterite, translated as "soliamos nadar"/"nadabamos"
Said tense refers to past situations, without relevant time limits.
¿Compartimos un sándwich, tu y yo?
6. [es] [cerrado]
7. [sucio]
8. [esta] [feliz](happy) [contento] (also happy so I don't know which one)
9.[esta] [triste]
10. [estan] [cerrado]
For me, I would say all the answers are correct, but if they want 1 answer then A. would be the best.
I am fluent in Spanish, so if you have any further questions, let me know ;)